title: Expression of DNMTs and genomic DNA methylation in gastric signet ring cell carcinoma.
abstract: The aim of the present study was to investigate the protein expression of DNA methyltransferases (DNMTs) and genomic DNA methylation status of genomes in gastric signet ring cell carcinoma (SRC). Immunohistochemistry was performed to analyze DNMT expression and methylated DNA immunoprecipitation microarray (MeDIP‑chip) and MeDIP quantitative real‑time PCR (MeDIP‑qPCR) were performed to analyze the genomic DNA methylation status in gastric SRC tissue. An increase in DNMT1 and decrease in DNMT3A expression in SRC tissue was observed compared with matched non‑cancerous tissue. However, expression of other DNMTs, DNMT2, DNMT3B and DNMT3L, was not found to differ significantly between carcinoma and control. The MeDIP‑chip assay revealed that methylation of gene promoters and CpG islands in SRC was higher than those in matched control tissue. However, MeDIP‑qPCR analysis demonstrated that specific tumor‑related genes, including ABL2, FGF18, TRAF2, EGFL7 and RAB33A were aberrantly hypomethylated in SRC tissue. Results of the current study indicate that gastric SRC may produce complex patterns of aberrant DNA methylation and DNMT expression.
authors.affiliation: Department of General Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China.
authors.forename: Miao
authors.initials: M
authors.lastname: He
authors.forename: Jing
authors.initials: J
authors.lastname: Fan
authors.forename: Rong
authors.initials: R
authors.lastname: Jiang
authors.forename: Wei-Xue
authors.initials: WX
authors.lastname: Tang
authors.forename: Zi-Wei
authors.initials: ZW
authors.lastname: Wang
mesh_terms: D000368:Aged; D018279:Carcinoma, Signet Ring Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018899:CpG Islands; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D000090205:DNA Methyltransferase 3A; D015254:DNA Modification Methylases / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D047468:Immunoprecipitation; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000097584:DNA Methyltransferase 3B
chemical_list: D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A; D015254:DNA Modification Methylases; D000097584:DNA Methyltransferase 3B; C000717967:DNMT3A protein, human; C412484:DNMT3L protein, human; C000619380:DNMT1 protein, human; C112218:TRDMT1 protein, human